Internal combustion engines can draw air into an intake manifold through an induction system that can be regulated by a throttle. The throttle may be electronically actuated, e.g., by a controller, which is also known as electronic throttle control (ETC). The air in the intake manifold can be distributed to a plurality of cylinders and combined with fuel to create an air/fuel mixture. The air/fuel mixture can be combusted within the cylinders to drive pistons that rotatably turn a crankshaft to generate drive torque. Exhaust gas resulting from combustion can be expelled from the cylinders.
Intake valves can control the flow of air (or the air/fuel mixture) into the respective cylinders. Similarly, exhaust valves can control the flow of the exhaust gas out of the respective cylinders. These valves can be electronically actuated, e.g., by a controller. By controlling the timing that the valves open and close, engine performance, fuel economy, and/or emissions can be adjusted. This is also known as variable valve timing (VVT). VVT operation, however, can depend on ETC operation because ETC controls the airflow into the intake manifold.